The objectives and methods of the macular photocoagulation study have been well outlined in the master grant application previously submitted. Please see manual of procedures (protocol) macular photocagulation study, February 1979. Particularly applicable is Chapter 2, Research Plan. This includes: 2.1.1. Objectives - ocular histoplasmosis; 2.1.2. Objectives - senile macular; 2.3. Major design characteristics.